Every year downhill skiing causes many serious knee injuries involving ligament and meniscal tears, despite the efforts that have been made in the industry to improve the bindings, the devices for attaching the boot to the ski, and therefore the skier or athlete to the skis.
These injuries often force the patient to quit skiing or practicing many other sports, or undergo major surgery, with certain risks and doubts, often very painful and long recoveries, changes in lifestyle with the respective work, family, professional, psychological and financial drawbacks resulting from the injury.
Other possible injuries while skiing, which follow knee injuries in number, are head and face injuries, but the use of a helmet to protect against these injuries is becoming increasingly widespread.
Currently, the annual total number of skiers per year between the United States and Europe is about 20 million.
The total number of accidents involving serious injuries entailing caring for and evacuating injured persons from the slope is about between two and four per every thousand. Out of one thousand days skied by a skier, one will be injured between 2 and four times (in the United States, this figure is about 3.5 per thousand days).
Skiing also becomes difficult on many occasions due to the amplification of the force that any uneven terrain will have through the large lever of the skies on the skier's foot, making the skier lose his or her path and causing instability.
As previously mentioned, skiing involves a high risk of knee ligament and meniscal injuries (between 30% and 40% of the total), among other injuries. Such injuries are frequently caused by the large forces that knees are subjected to because of the stress transmitted thereto through the rigid boot from the skis, which act as large levers as illustrated in FIG. 1A.
There are different knee injuries, but the most common ones in skiing are external lateral ligament tears (between 20 and 25% of injuries) and the anterior cruciate ligament tears (between 10 and 15% of injuries).
The injury to the external collateral ligament normally affects beginners and intermediate level skiers, who ski mainly in the wedge position, with the feet facing inwards, and who are injured during a fall, when the skis cross over one another or the wedge opens up. Injury to the external lateral ligament can occur in more experienced skiers usually when a ski strikes against an obstacle, the ski opens up and the leg tries to hold on to it.
The injury to the anterior cruciate ligament occurs under different conditions, especially in more experienced skiers, and can occur, for example:                When the rear part of the ski acts as a lever with the boot, exerting a rotational force, twisting and bending the knee;        When the skier falls backwards during a jump and instinctively straightens his or her leg and therefore falls on the rear part of the ski, forcing the rear part of the boot against the calf thereby deviating the tibia under the femur and tearing the cruciate ligament; or        When a skier is upright and is hit from behind on the lower part of the leg, forcing the tibia forwards with the subsequent damage to the cruciate ligament.        
Other injuries include damage to the meniscus (between 5 and 10% of all injuries), caused by torsional stress applied to the flexed knee and usually caused when an obstacle is struck at a high speed.
Currently, bindings holding the boot to the ski are relied upon for reducing the risk of injury, but they do not adequately prevent such risk. Bindings are designed so that the boot is released from the ski when a specific and previously established pressure limit is surpassed. However, depending on the posture of the leg at the time of the demand of the force and of other factors, such as the severity of the impact, it is possible that the binding does not behave as expected. In such cases, the binding does not come undone and the boot is not released from the ski at the appropriate time or at all, frequently causing the ligaments of the knee to tear before the mechanism can release the boot.
This system furthermore forces the skier to choose a certain setting. If the binding is too tight, it is hard for the ski to separate from the boot at a torsion of the ski that is large enough to risk injury to the knee. If, on the other hand, the bindings are too loose, a skier may, at an inconvenient moment, involuntarily lose a ski, which could also cause a serious injury.
Nor do current bindings contribute to the stability of skis or to the skier's desire to stay on his or her path.
As previously mentioned, these knee injuries usually bring about an expensive surgical intervention with a long and uncomfortable recovery, results that are not always satisfactory and significant repercussions in terms of work, family, etc.
The known devices of the state of the art, do not provide a protection and control over the skis as the one of the exoskeleton of the present invention.
Different devices for preventing ski injuries are known. For example, United States patent document number US-4136404-B1 discloses an athletic leg brace apparatus configured to be connected to the sides of a ski boot and divided into two parts along the leg by a hinge at the height of the knee, such that an upper part is attached to the thigh and a lower part to the boot. The device allows flexion and extension movement of the leg, restricting the lateral flexion of both parts of the leg and allowing the transmission of lateral forces of the skier's legs to the lateral parts of the boot. In other words, the purpose of this device is to reduce the lateral flexion of a skier's legs when he or she is skiing, so as to protect the bones of the leg, not the joints, in the event of flexion. Furthermore, this device does not protect the leg in the case of torsion, which is the stress causing the most common and significant knee injuries, especially when the knee is extended. Another limitation of the mechanism protected by the mentioned US patent is that, since the leg is firmly attached to the boot by the mechanism of the described invention, the freedom of movement is quite compromised when the knee is flexed, negatively affecting the skiing experience, unlike the present invention. Additionally, the device described in US-4136404-B1 has no element for attachment to or support by the waist. All the stress is confined exclusively to the leg. An object of several embodiments of the present invention, on the other hand, is to use the waist as a strong area of the body for supporting the entire reinforcement structure and preventing leg injuries. Nor does US-4136404-B1 incorporate any ski control device. Another object of several embodiments of the present invention, however, is to allow efficient and effective control of the skis at all times. This involves a significant improvement of the active safety conditions in addition to making the skiing experience much more satisfactory.
Another limitation of the US-4136404-B1 is that since the leg is “embraced” at the thigh and attached to the boot in the manner described in that patent, the freedom of movement is quite compromised, negatively affecting the skiing experience, unlike the device according to the present invention.
An object of the present invention is to allow improved freedom of movement of the leg at all times, except that the leg is supported by the protective structure at those times when it is necessary and particularly in the direction of unwanted movements. In other words, it allows improved or complete freedom of wanted movements and restricts unwanted movements induced by the ski.
U.S. Pat. No. 3,947,051-B1 describes a binding for a ski boot with a transmitter located between the skier's leg and boot to initiate the “release” operation of the binding during falls, particularly forward falls. The transmitter detects an excessive force between the leg and the boot, thus transmitting an instruction to release the binding, preventing leg injuries in the skier. However, as will be understood, the present invention is completely different from the foregoing:                It does not require the replacement of the boot-ski binding mechanism, but rather can be complementary to it;        It is not limited to the boot-ski attachment, and provides a boot-leg and, in several of the preferred embodiments, hip connecting elements (exoskeleton);        elements of the present invention can transmit the torsion or torque generated at the foot due to the lever effect of the ski to the entire exoskeleton structure and through it to the strong areas of the leg and, in most of the preferred embodiments, to a part located at the skier's waist or hips, thereby protecting against dangerous torsion of the knee joint;        the device, being attached to strong areas of the body, can withstand the torsion or torque generated in the foot due to the lever of the ski in limit or extreme positions that may injure the knee, such that the resultant forces are not transmitted to the much weaker knee joint, and which until now no system or mechanism has been able to effectively protect as proven by the previously mentioned statistics;        the present application significantly reinforces the corporal structure in the areas of the body that are most involved in skiing, which allows tighter setting of the bindings with the assurance that no injury will occur, because in most cases the skier will be supported by the reinforced structure of the exoskeleton, and in extreme cases, the binding would come undone without affecting the structure of the knee or any other leg joint or bone.        
None of the previous features or functionalities are present in U.S. Pat. No. 3,947,051-B1, whereas the present invention allows one to achieve this functionalities.
A system that significantly increases the skier's resistance to unwanted movements of the ski is also an object of the present invention. This system diverts part of the torque that an unwanted rotation of the ski causes on the foot to the structure formed by the exoskeleton, to the strong parts of the leg to which the structure is attached to and, in several of the preferred embodiments, the waist or hips. In addition to increasing safety, this helps considerably in controlling the skis. This feature is also not present in the device described in US-3947051-B1 or other conventional support mechanisms.
United States patent application publication number US-2006260620-A1 describes a lower extremity exoskeleton that is coupled to a person and configured such that both leg supports are used to be supported on the ground when the user is stopped. The exoskeleton is formed by a link in the thigh, another one in the calf and two joints at the height of the knee, these joints allow the extension and flexion of the thigh link and of the calf link. The exoskeleton is attached to the hip through joints allowing extension and flexion. The energy for moving the exoskeleton is provided by the user thereof. This device can be applied to persons who require aid in walking or who need to be stopped, bearing and carrying loads and weights, i.e., the purpose of the device is to increase the user's ability to bear large weights when he or she is walking or is stopped.
International patent application number PCT/US2006/014227 describes a variant of the previously described device, further incorporating a motor so as to achieve a greater increase in the strength of the person using the exoskeleton.
Unites States patent application number US-2006260620-A1, which includes an anchoring to the hip, is structured to achieve results that are different from those of the present invention. As previously noted, this application is directed to a system for increasing the ability to bear large loads, to rest while standing or to substitute the lack of strength in weak legs. As such, this system is not useful for practicing a sport that is as dynamic and that requires as much flexibility as skiing. Rather, it merely has the purpose of increasing the load capacity, whereas as explained in this specification, the present invention is structured to increase resistance, not strength, against such things as unwanted rotations of a ski and other potentially dangerous movements, as well as increasing ski control.
The system described in United States patent application publication number US-2006260620-A1 is designed to work vertically with movements similar to those carried out while walking, counteracting forces of gravity, but not to resist rotational movements in a horizontal plane, like the invention described herein, which is particularly applicable for snow skiing.
The artificial hip joint described in United States patent application publication number US-2006260620-A1 does not have a mechanism allowing the natural rotation about all the natural axes of the legs and at the same time limiting the potentially injurious angular movement of the legs. On the other hand, the present invention provides a mechanism especially designed to allow all the freedom of movement necessary for such activities as skiing, while preventing unnatural movements that may cause injuries. The present invention is especially useful for protecting against extreme rotations of the foot, being designed to support rotational forces or torques due to the large lever that is attached to the skier's leg, i.e., the ski, which situation does not occur in the application of the device describe in United States patent application publication number US-2006260620-A1.
The artificial knee joint and artificial ankle joint of the device described in United States patent application publication number US-2006260620-A1 do not have any mechanism allowing the natural movements necessary for activity such as skiing, and which at the same time protects the joints against movements or positions of the knee in particular, and the leg in general, that can cause injuries. On the other hand, the present invention does provide these mechanisms in the artificial joints, on one hand to provide all the necessary range of movements and on the other hand to limit or prevent those movements or positions which may be injurious to the leg in general and the knee in particular, especially focusing on the protection against severe rotations of the foot, or of the body around the foot, which may occur involuntarily during physical activities such as skiing.
Additionally, US-2006260620-A1 has no mechanism contributing to greater control of the skis by the skier, whereas in certain aspects of the present invention, a mechanism is provided that is especially designed for the skier to have at all times added control over the skis so that if a ski is in danger of losing the path that the skier wants to follow due to uneven terrain or any other reason, this mechanism would automatically prevent such diversion. The skis will always stay on the path required by the skier regardless of uneven terrain, irregularities in the snow or different snow qualities.
No feature similar to the foregoing is described in US-2006260620-A1, nor can any element thereof be useful in similar circumstances, much less solve this problem considered by the present invention.
A device that solves many problems existing in the state of the art devices as well as other problems is describe and claimed in the co-pending U.S. patent application Ser. No. 12/103,196 titled “Exoskeleton”, filed on Apr. 15, 2008, for a new exoskeleton invented by the same inventors of the present invention. This co-pending application no. is incorporated herein in its entirety by reference. The present invention provides additional features and can be used in combination with aspects of the exoskeleton described in the co-pending application.
There are no prior known protective devices offering a minimum assurance of preventing such injuries, allowing in turn the freedom of movements necessary for skiing, or additionally control of the skis while skiing.